A Density Functional Theory-Based Scheme to Compute the Redox Potential of a Transition Metal Complex: Applications to Heme Compound

We estimated the redox potential of a model heme compound by using the combination of our density functionals with a computational scheme, which corrects the solvation energy to the normal solvent model. Among many density functionals, the LC-BOP12 functional gave the smallest mean absolute error of 0.16 V in the test molecular sets. The application of these methods revealed that the redox potential of a model heme can be controlled within 200 mV by changing the protonation state and even within 20 mV by the flipping of the ligand histidine. In addition, the redox potential depends on the inverse of the dielectric constant, which controls the surroundings. The computational results also imply that a system with a low dielectric constant avoids the charged molecule by controlling either the redox potential or the protonation system

Theoretical investigation of solar energy conversion and water oxidation catalysis

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 169-196).Solar energy conversion and water oxidation catalysis are two great scientific and engineering challenges that will play pivotal roles in a future sustainable energy economy. In this work, I apply electronic structure theory and molecular dynamics simulation methods to understand some of the detailed mechanisms behind solar energy conversion and water oxidation catalysis. I will present a detailed atomistic picture of charge separation processes at a donor-acceptor interface between two organic semiconductor materials in an organic photovoltaic device. This will be followed by an investigation of the water oxidation mechanism of a homogeneous ruthenium water-splitting catalyst and a heterogeneous cobalt phosphate water-splitting catalyst. I will also introduce several advances in theoretical methods that allow us to more accurately compute observables that are critically relevant to the operation and performance of these materials and devices.by Lee-Ping Wang.Ph.D